Search results
Results From The WOW.Com Content Network
Peptide bond. In organic chemistry, a peptide bond is an amide type of covalent chemical bond linking two consecutive alpha-amino acids from C1 (carbon number one) of one alpha-amino acid and N2 (nitrogen number two) of another, along a peptide or protein chain. [1]
This suggests a possible mechanism by which alpha sheet may promote amyloid aggregation; the peptide bond has a relatively large intrinsic electrostatic dipole, but normally the dipoles of nearby bonds cancel each other out. In the alpha sheet, unlike other conformations, the peptide bonds are oriented in parallel so that the dipoles of the ...
Typically, the hydroxyl group of a serine (rarely, threonine) or the thiol group of a cysteine residue will attack the carbonyl carbon of the preceding peptide bond, forming a tetrahedrally bonded intermediate [classified as a hydroxyoxazolidine (Ser/Thr) or hydroxythiazolidine (Cys) intermediate].
Disulfide bonds Interlocked SS symbol or a zigzag, like a stylized lightning stroke. Prosthetic groups or inhibitors Stick figures, or ball & stick. Metals Spheres. Shading and colour Shading or colour adds dimensionality to the diagram. Generally, the features at the front are the highest in contrast and those towards the back are the lowest.
The standard hydrogen-bond definition for secondary structure is that of DSSP, which is a purely electrostatic model. It assigns charges of ±q 1 ≈ 0.42e to the carbonyl carbon and oxygen, respectively, and charges of ±q 2 ≈ 0.20e to the amide hydrogen and nitrogen, respectively. The electrostatic energy is
The α-carbon (alpha-carbon) refers to the first carbon atom that attaches to a functional group, such as a carbonyl. The second carbon atom is called the β-carbon ( beta -carbon), the third is the γ-carbon ( gamma -carbon), and the naming system continues in alphabetical order.
The ω angle at the peptide bond is normally 180°, since the partial-double-bond character keeps the peptide bond planar. [3] The figure in the top right shows the allowed φ,ψ backbone conformational regions from the Ramachandran et al. 1963 and 1968 hard-sphere calculations: full radius in solid outline, reduced radius in dashed, and ...
Preliminary binding of a ligand near to the entrance breaks hydrogen bonds S212-E474, S207-H172 in the open form of CYP2B4 and hydrogen bonds E218-A102, Q215-L51 are formed that fix the entrance in the closed form as the HB plot reveals. The second step is the transfer of the first electron from NADPH via an electron transfer chain. For the ...